# Swap (v1)

In this section, to illustrate all three possible types of a swap, we will do following exchange chain

1. swap 1 TON to STON (ton to jetton swap)
2. swap STON to GEMSTON (jetton to jetton swap)
3. swap GEMSTON back to TON (jetton to ton swap)

## Swap TON to jetton

```typescript
import { TonClient, toNano } from "@ton/ton";
import { DEX, pTON } from "@ston-fi/sdk";

const client = new TonClient({
  endpoint: "https://toncenter.com/api/v2/jsonRPC",
});

const router = client.open(new DEX.v1.Router());

// swap 1 TON to STON but not less than 1 nano STON
const txParams = await router.getSwapTonToJettonTxParams({
  userWalletAddress: "", // ! replace with your address
  proxyTon: new pTON.v1(),
  offerAmount: toNano("1"),
  askJettonAddress: "EQA2kCVNwVsil2EM2mB0SkXytxCqQjS4mttjDpnXmwG9T6bO", // STON
  minAskAmount: "1",
  queryId: 12345,
});
```

To execute the transaction, you need to send a transaction with these parameters to the blockchain. This code will be different based on the wallet you are using to send the tx from, so please check our [doc section about transaction sending guide](https://docs.ston.fi/developer-section/common/transaction-sending) with examples for different libraries.

## Swap jetton to jetton

```typescript
import { TonClient, toNano } from "@ton/ton";
import { DEX, pTON } from "@ston-fi/sdk";

const client = new TonClient({
  endpoint: "https://toncenter.com/api/v2/jsonRPC",
});

const router = client.open(new DEX.v1.Router());

// swap 1 STON to GEMSTON but not less than 1 nano GEMSTON
const txParams = await router.getSwapJettonToJettonTxParams({
  userWalletAddress: "", // ! replace with your address
  offerJettonAddress: "EQA2kCVNwVsil2EM2mB0SkXytxCqQjS4mttjDpnXmwG9T6bO", // STON
  offerAmount: toNano("1"),
  askJettonAddress: "EQBX6K9aXVl3nXINCyPPL86C4ONVmQ8vK360u6dykFKXpHCa", // GEMSTON
  minAskAmount: "1",
  queryId: 12345,
});
```

To execute the transaction, you need to send a transaction with these parameters to the blockchain. This code will be different based on the wallet you are using to send the tx from, so please check our [doc section about transaction sending guide](https://docs.ston.fi/developer-section/common/transaction-sending) with examples for different libraries.

## Swap jetton to TON

```typescript
import { TonClient, toNano } from "@ton/ton";
import { DEX, pTON } from "@ston-fi/sdk";

const client = new TonClient({
  endpoint: "https://toncenter.com/api/v2/jsonRPC",
});

const router = client.open(new DEX.v1.Router());

// swap 1 GEMSTON to TON but not less than 1 nano TON
const txParams = await router.getSwapJettonToTonTxParams({
  userWalletAddress: "", // ! replace with your address
  offerJettonAddress: "EQBX6K9aXVl3nXINCyPPL86C4ONVmQ8vK360u6dykFKXpHCa", // GEMSTON
  offerAmount: toNano("1"),
  proxyTon: new pTON.v1(),
  minAskAmount: "1",
  queryId: 12345,
});
```

To execute the transaction, you need to send a transaction with these parameters to the blockchain. This code will be different based on the wallet you are using to send the tx from, so please check our [doc section about transaction sending guide](https://docs.ston.fi/developer-section/common/transaction-sending) with examples for different libraries.

## Recommended gas values

Below are recommended values for TON sent and forward gas for each type of the swap:

| Type                 | Tx TON                | Forward TON |
| -------------------- | --------------------- | ----------- |
| `pTON` -> `Jetton`   | `swap_amount + 0.185` | `0.185`     |
| `Jetton` -> `Jetton` | `0.22`                | `0.175`     |
| `Jetton` -> `pTON`   | `0.17`                | `0.125`     |

#### Formulas:

**`pTON` -> `Jetton`**

```typescript
// pton_transfer + (pay_to + jetton_transfer) * 2 + (jetton_notification + swap)
fwd_amount = 0.01 + (0.02 + 0.045) * 2 + 0.045; // = 0.185
// jetton_transfer + fwd_amount
tx_amount = swap_amount + fwd_amount; // = swap_amount + 0.185
```

**`Jetton` -> `Jetton`**

```typescript
// (jetton_notification + swap) + (pay_to + jetton_transfer) * 2
fwd_amount = 0.045 + (0.02 + 0.045) * 2; // = 0.175
// jetton_transfer + fwd_amount
tx_amount = 0.045 + fwd_amount; // = 0.22
```

**`Jetton` -> `pTON`**

```typescript
// (jetton_notification + swap) + (pay_to + pton_transfer) * 2
fwd_amount = 0.045 + (0.02 + 0.02) * 2; // = 0.125
// jetton_transfer + fwd_amount
tx_amount = 0.045 + fwd_amount; // = 0.17
```